1. Dirk Grunwald Department of Computer Science University of Colorado at Boulder July 7, 2011

2.  Design and Build GENI Cognitive Radio wideband radio (≥ 100MHz) network testbed  Current radio by Peter Wolniansky  100Mhz-7500Mhz / 40Mhz select  Switched filter bank  Superheterodyne radio with a sharp IF filter, allowing measurements as close as 5-10 MHz from strong interferers.  Soise floor is -101dBm for a 8MHz channel  Bonded to a commodity (Avnet) FPGA board, working on support for multi-FPGA systems  Up to 4 radios on one FPGA 2

3.  Most campuses using 802.11 WiFi  WLAN: Short range due to limited power, design  Limited spectrum choices (2.4Ghz & 5Ghz), but a lot of spectrum (esp. in 5Ghz band)  High performance for limited ranges - 30- 100meter range, 1-200mb/s  Limited quality of service (voice, video)  Limitations based on technology and regulation 3

4.  WiMAX & LTE designed for wide area mobile wireless networks  Better network integration  Better device and user authentication, better security, fast handover  Covers 1km-30km  Goal is coverage, not capacity  Throughput depends on bandwidth (Hz) and signal quality  10Mhz - ~25MHz down, 6MHz up 4

5.  Wider coverage means fewer AP’s, but each AP is more important  Most LTE / WiMAX spectrum is “line of sight” – buildings get in the way  Spectrum planning tools, follow-up measurement more important  Spectrum planning tools use frequency, height & “clutter” 5

6.  3500 MHz 700 MHz  Lower frequencies have wider coverage at the same power  good for coverage, but less available spectrum  More coverage usually means more interference  Technologies (LTE/WiMAX) are design for specific frequencies - future wireless network standard will use “TV White Spaces” 6

7.  LTE is “telecom”, WiMax is “data” – moving from one to the other is more about the “backend network” than the AP’s  Much of your (CIO) planning for wide-area wireless is largely independentw of underlying technology  At higher frequencies, spectrum planning is very important, but the accuracy of such spectrum planning is variable 7